1. Field of the Invention
The present invention relates to an image recording apparatus for recording an image on a recording medium, and more particularly, to a recording apparatus that is supplied with power from a fuel battery or cell to execute a recording operation.
2. Description of the Related Art
Since inkjet recording systems can easily print data in colors and are suitable to reduce noise and cost, they are widely used in printers, facsimiles, and the like.
As host apparatuses such as personal computers and the like are reduced in size, there is a tendency to also reduce in size recording apparatuses such as printers, copy machines, facsimiles, and the like. In particular, since mobile personal computers called note book computers are not provided with a recording apparatus oridinarily, a mobile recording apparatus is necessary to record information by the mobile personal computers outside of an office. Thus, it is required that the mobile recording apparatus be small in size, light in weight and driven by a battery. Since the inkjet recording apparatus can be easily reduced in size, printers of a size that is easy to carry, that is, mobile printers, are employed in many cases. The mobile printer is provided with a storage battery such as a secondary battery, a dry-cell battery, and the like to cope with a requirement for battery drive as disclosed in, for example, Japanese Patent Laid-Open No. 11-292341.
While storage batteries such as secondary batteries, dry-cell batteries, and the like are continuously being improved and the capacity thereof being increased, the capacity has not been yet greatly increased to several or several tens of times, and it is difficult to expect to greatly reduce the size and weight of the recording apparatus using known storage batteries. Further, the secondary battery is troublesome in that it must be charged, whereas the dry-cell battery has a problem in that it impacts the environment because it is disposable, while it need not be charged.
In view of the above circumstances, attention is paid to fuel batteries. The fuel battery generates power by an electrochemical reaction of hydrogen with oxygen through a catalyst and is vigorously studied all over the world with an expectation to serve as a clean energy source for the next generation. Development of fuel batteries has preceded in the fields of electric vehicles and small power generation systems. However, as disclosed in, for example, Japanese Patent Laid-Open No. 07-201348, ultra small fuel batteries, which can be used as a power supply for small electronic equipment such as medical micro-machines, mobile phones, and the like, have recently been made for testing. The fuel battery can generate power that is about ten times larger than that of a lithium-ion battery used in almost all the electronic equipment at present. Further, the fuel battery need not be charged, unlike an ordinary storage battery, and can be used only by being supplied with fuel.
Further, the fuel battery is advantageous in that fuels such as methanol and the like can be obtained at a low cost and the environment is less affected thereby. Accordingly, when a small fuel battery is practically used, it can be applied to a power source of the printer, which can realize a smaller mobile printer that is more friendly to the environment.
However, the fuel battery must discharge carbon dioxide, water, and the like, which are produced in power generation, to the outside of an apparatus, and this is a large problem when the fuel battery is mounted on electronic equipment. To cope with this problem, a method of vaporizing generated water and discharging it as vapor to the outside of the apparatus has been proposed. However, this method is disadvantageous in that cost is increased because a vaporization mechanism is necessary. Further, there is a possibility that the vapor may be liquefied again and reform as dew drops in a low temperature/high humidity atmosphere as in rainy days and the like, thereby causing the recording apparatus to malfunction.
A function for notifying a user of a remaining amount of a battery is very important in battery-driven electronic equipment. If it possible to warn that the remaining amount of the battery is low before the electronic equipment is interrupted by a dead battery, the user can prepare a spare battery in advance and can replace it for the dead battery, thereby the interruption of the electronic equipment during use can be prevented. A method of detecting near depletion of fuel in a fuel battery includes a method of detecting the pressure of a hydrogen gas used in power generation, a method of calculating the amount of power consumption by hardware, and the like.
However, any of these methods has a problem in that the cost and size of electronic equipment is increased. Thus, there is contemplated a method of calculating the amount of power consumption by software. However, this method has a technical problem in that accuracy in detection is low because the remaining amount of the battery is calculated by subtracting the estimated amount of power consumption from a predetermined initial remaining amount and in that this method cannot be used when the remaining amount of a replaced tank is the predetermined initial remaining amount, that is, the replaced tank is filled up.